The conversion or scavenging of environmental vibration to voltage differential can provide free and clean energy. In addition, environmental vibration is present in a multitude of operations, activities, and the like, and such vibrations are not significantly influenced by environmental conditions such as temperature, humidity, amount of sunlight, etc. As such, environmental vibration is one of the most attractive power sources that can provide consistent power for extended periods of time.
Vibration scavenging, also known as energy scavenging or energy harvesting, converts vibration to electrical energy using a piezoelectric material, the piezoelectric material converting mechanical strain into a voltage differential by creating a charge separation across a dielectric material. In particular, a piezoelectric energy harvesting device affords for bending of a piezoelectric strip or plank that is secured at one end and movable at an opposing end. The bending of the piezoelectric material results in elastic deformation thereof, the elastic deformation being transformed or converted into electrical energy.
Energy generated by such a piezoelectric energy harvesting device is proportional to the average mechanical strain, i.e. elastic deformation, that the material experiences during bending. In addition, piezoelectric materials are typically stiff in nature and thus more effective and useful for relatively high-frequency applications. However, environmental vibration is typically low frequency. As such, heretofor piezoelectric energy harvesting devices have had limited success in part due to environmental vibration typically being of small magnitude and low frequency and/or the expense of providing a plurality of devices that can harvest an appreciable amount of energy. Therefore, an energy harvesting device that can take advantage of small magnitude and low frequency vibrations that are present in many operations, activities, and the like using piezoelectric materials and is affordable to fabricate would be desirable.